Coronary Heart Disease (CHD) is the leading cause of death in older women and accounts for a large proportion of illness and disability in women 65 years of age and older. However, the potential risk factors associated with the development and progression of CHD in elderly women remain poorly understood. The proposed research will examine the complex interactions between the traditional cardiovascular risk factors, in particular lipoprotein and apoprotein levels, and certain genetic and host characteristics and lifestyle habits. Specifically, this investigation will: 1. described the distribution and interrelationships of lipoproteins and apoproteins in a large cohort of elderly women recruited for a prospective study of hip and wrist fractures; 2. examine the relationship of important host and lifestyle factors to the lipoprotein and apoprotein levels; 3. examine the population frequencies of phenotypes of the polymorphisms of apoprotein A-IV and E and to determine whether these polymorphisms are associated with specific patterns of lipo and apoproteins; and 4. test the hypothesis that the degree to which lifestyle and host characteristics explain the variability in lipoproteins and apoproteins depends on the genetic make up of the individual. This study is ancillary to the multicenter Study of Osteoporotic Fractures (SOF) and will involve 1000 of the 2400 women over the age of 65 recruited for SOF. It is believed that this study has the potential to advance our understanding of the risk factors for CHD in elderly women. The proposed study represents a new direction for epidemiologic studies by incorporating genetic markers and analyzing the degree to which these genetic markers can explain the variability in lipoprotein and apoprotein levels.